Earnings Per Share and Common Stock - Reconciliation of Information Used to Compute Basic and Diluted EPS (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings Per Share [Abstract]
Net income attributable to common shareholders	$ 765	$ 469	$ 258
Less: preferred stock dividends declared	2	2	2
Net income available to Howmet Aerospace common shareholders - basic	763	467	256
Net income available to Howmet Aerospace common shareholders - diluted	$ 763	$ 467	$ 256
Average shares outstanding - basic (in shares)	412	416	430
Effect of dilutive securities:
Stock and performance awards (in shares)	4	5	5
Average shares outstanding - diluted (in shares)	416	421	435